A β-lactam is a 4-membered ring structure as shown in FIG. 1. The ring is considered to be essential for antibiotic function within the class of antibiotics known as β-lactam antibiotics. The β-lactam antibiotics are divided into subclasses based on additional structural elements. Two classes that the present invention will impact are the monobactams (exemplified by aztreonam and carumonam) and the carbapenems (exemplified by ertapenem) (FIG. 2). In particular, carbapenems are produced by chemical synthesis rather than by fermentation, as is usual for β-lactam antibiotics. The total chemical synthesis of carbapenems was pioneered by Merck scientists in the 1980s during their efforts to produce the natural carbapenem thienamycin. Since the carbapenems have shown themselves to be an important basic structure for antibiotic production, a number of intermediates toward the synthesis of these structures have been commercialized (see FIG. 3).